Define mean and median for a set of data

The mean is the average number of a data set gotten by adding all the numbers then dividing by two.

the median is the middle number in a sorted set of data,either sorted in ascending order or descending order.

I hope this helps

4 and 5)16.97 or 12√2

6)15.59 or 9√3

7)y = 15.59 or 9√3     x =27

8)17.80